Heat exchanger

ABSTRACT

Heat exchanger with a cylindrical housing and heat exchanger elements arranged axially and centrally of the housing; two connections in the cylindrical wall of the housing; two partitions facing the connections, and lying against the heat exchanger elements, and forming a flow space containing the heat exchanger elements and being in contact with the connections only by throttling gaps between partition and tubular wall. The medium flowing through the flow space being widened out over the entire length of the heat exchanger elements.

il'nited States Patent [191 Maser et a1.

[451 May 29, 1973 1 HEAT EXCHANGER [75] Inventors: Paul Moser, Winterthur; Tadeusz Zaba, Wettingen, both of Switzerland Brown Boveri-Sulzer Turbomaschinen Aktiengesellschaft, Zurich, Switzerland Filed: July 12, 1971 Appl. No.: 161,467'

[73] Assignee:

[30] Foreign Application Priority Data July 17, 1970 Switzerland ..109l5/70 user. ..165/160 rm. Cl. ..1 ..F28d 7/00, F28f 9 22 Field of Search 165/159, 160, 161,

[56] References Cited UNITED STATES PATENTS 3,267,693 8/1966 Richardson et a1 ..165/l60 X 3,326,280 6/1967 Bosquain et a1. ..l65/l61 FOREIGN PATENTS OR APPLICATIONS 153,783 10/1953 Australia ..165/161 Primary Examiner-William F. ODea Assistant ExaminerWilliam C. Anderson Attorney-Austin P. Dodge and Robert A. Ostmann by throttling gaps between partition and tubular wall.

The medium flowing through the flow space being widened out over the entire length of the heat exchanger elements.

7 Claims, 8 Drawing Figures I l/I'l O O O 0 0 0 0 0 PATENIEU k-1- 2 Hm 3; 735 e1 1 SHEET 1 OF 3 PATEN'IED wsreg m5 3; 735 81 1 1 HEAT EXCHANGER BACKGROUND OF THE INVENTION The invention concerns a heat exchanger for heat exchange between two media, having a cylindrical housingwith a cylindrical wall and two tube plates, by means of which tube plates tubes are led through the housing substantially parallel to the longitudinal axis of the latter, an inlet connection being inserted on one side and on outlet connection on the other side of the cylindrical wall, by means of which connections the first of the two media flows through the housing while sweeping over the outer surface of the tubes, while the second medium flows through the tubes.

The efficiency of such apparatus can be increased, other conditions remaining the same, by a better distribution of the flow of the first medium over the largest possible part of the outer surface of the tubes. This requirement can be met by the use of axially shorter and radially wider housings. In the construction of such ap-' paratus of larger capacities, restrictions are often imposed for reasons of space or transport.

If the diameter of the apparatus is limited, its length must be increased corresponingly, it being necessary to ensure the desired throughput by means of expensive additional admission and discharge connections to the shell.

If there are high capacities, relatively high pressures and temperature differences, in the case of large and long housings, the said additional connections are economically inadmissible for strength reasons, and a plurality of sets of apparatus of lower capacity must be used for heat exchange.

4 SUMMARY OF THE INVENTION The problem underlying the present invention is to obviate the difficulties enumerated with regard to the construction of such large apparatus, while retaining the relatively cheap construction of a simple cylindrical housing.

According to the invention, the problem is solved in thatthe tubes lie in a tube assembly arranged centrally of the housing, and in that two partitions on the sides of the tube assembly facing the connections lie against the said tube assembly over the entire length of the housing and form between each other a flow-through space, which is in communication at its respective ends with the two connections substantially only by means of a respective throttling gap left between one of the partitions and the cylindrical wall, a first stabilisation space, i.e., a distributing space being formed between the inlet connection and the first throttling gap in the direction of flow of the first medium, and a second stabilisation space, i.e., a collecting space being formed between the second throttling gap and the outlet connection. It is particularly advantageous to provide a stabilisation space downstream of the first throttling gap and upstream of the tube assembly. A fourth stabilisation space is preferably located downstream of the tube assembly and upstream of the second throttling gap.

It is advantageous if the tube assembly has a rectangular cross-section, and furthermore if the area of passage of the first throttling gap is smaller than thatof the second throttling gap.

It is expedient if the housing, at least in the range of the path of the first medium, leading from the inlet connection to the tube assembly, is constructed in double jacketed fashion, the intermediate space of the double jacket being in communication with the path of the first medium leading from the tube assembly to the outlet connection.

BRIEF DESCRIPTION OF THE DRAWING heat exchanger according to a second embodiment,

FIG. 4 shows a crosssectional on the line IIIIII in FIG. 3,

FIG. 5 shows an axial section on the line V-V in FIG. 4,

FIG. 6 shows an axial longitudinal section through a heat exchanger according to a third embodiment,

FIG. 7 shows a cross-section on the line VII-VII in FIG. 6,

FIG. 8 shows a section on the line VIIIVIII in FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment example of the heat exchanger shown in FIGS. 1 and 2, the latter has a cylindrical housing 1 consisting of a cylindrical wall 2 and two tube plates 3. Tubes 4, as heat exchanger elements, are passed through the tube plates 3 and through the housing 1 parallel to its longitudinal axis. At one side, an inlet connection 5 is inserted in the wall 2, and at the opposite side an outlet connection 6. The first of the two media flows through these connections 5 and 6 and sweeps over the outer surfaces of the tubes 4. The second medium flows inside the tubes 4. The tubes 4 are situated in a tube assembly 40, arranged centrally of the housing and having a rectangular cross-section. Extending over the entire length of the housing I on the sides of the tube assembly 40 facing the connections 5 and 6, there are two partitions 7 and 7', between which a through-flow space S is formed. This flow space communicates with the connections 5 and 6 only by way of two throttling gaps 9 and 9', which are left between the shell 2 and loose edges of the partitions 7 and 7. A distributing space 10 is formed between the inlet connection 5 and the first throttling gap 9 in the direction of flow of the first medium, and a collecting space 11 is formed between the second throttling gap 9' and the outlet connection 6. The area of passage of the first throttling gap 9 is less than that of the second throttling gap 9.

The stream of the first medium comes through the inlet connection 5 into the distributing space 10 where it widens out substantially laterally transversely of the direction of flow over the entire housing length. Throttled by the first throttling gap 9, the stream enters over the entire length of the housing into the stabilization space 1% of the flow space 8, where it widens out over the entire width of the flow space. Thus distributed uniformly over the opening area of the flow space, it sweeps uniformly substantially over the entire outer surface of the tubes 4. After passing through the tube assembly 40, the stream is discharged, through space 18, into the collecting space 11 by way of the second throttling gap 9 throttling it. The first medium leaves the housing 1 through the outlet connection 6. Corresponding to the requirement of a flowing discharge of the stream, the second throttling gap 9, compared with the first throttling gap 9, has an area of passage which is larger but is similar in form.

Since, according to the invention, good utilization of the entire surface of the tubes for heat exchange is achieved, and since the hitherto necessary built-on structures with the connections are no longer necessary, the heat exchangers can be easily dimensioned concerning strength because there-are no unfavourable transitions between conduits and shell. The apparatus is simple to make. Additional structural volumes are saved. Construction is cheap.

In the embodiment example of the heat exchanger according to FIGS. 3 to 5, covers for conducting and distributing the second medium flowing through the tubes 4 are shown mounted at the ends of the heat exchanger (FIG. 3) on the tube plates 3, as is common knowledge. The housing 1 is made in the form of a double jacket for preventing the hot first medium from coming into contact with the cylindrical wall 2. A double jacket 12 extends over the entire length of the housing in the region of the path of the first medium leading from the inlet connection 5 to the flow space 8, and its inner wall part 13 is connected to an inner jacket 13', with which the inlet connection 5 is provided. An intermediate space 14 of the double jacket 12 is in communication on the one hand with the path leading from the tube assembly 40 to the outlet connection 6, and on the other hand with the collecting space 11. The flow space 8 is connected to the inlet connection 5 only by the first throttling gap 9 and to the outlet connection 6 only by the second throttling gap 9'. An insignificant part of the medium flows through the intermediate space 14 to the collecting space 11.

The connections 5 and 6 are situated in the middle of the shell 2 (FIG. 3). The areas of passage of the two throttling gaps 9 and 9 are symmetrical about a transverse plane passing through the axis of inlet 5 and outlet 6 (see FIG. 5). i

In this embodiment example of the heat exchanger, the path of the stream of the first medium has remained substantially the same. In the region of the not yet cooled first medium, that is to say in the distributing space and in the space 18 of the flow space 8 of the tube assembly 40 in the direction of flow, the cylindrical wall 2 of the housing 1 is protected from thermal stressesyThe essential part of the first medium is discharged through the second throttling gap 9 into the collecting space 11, a small portion of the medium taking a path from the space 18' of the flow space 8, following in the direction of flow through the intermediate space 14 of the double jacket 12 into the collecting space 11.

Due to the described protection of the cylindrical wall 2 from the heat influences of the hot first medium, no deformation occurs through local heating on the wall 2 and connections 5 and 6. In most cases, thermal insulation of the wall 2 from the surroundings is unnecessary.

In the embodiment example of the heat exchanger shown in FIGS. 6 to 8, two covers are shown, mounted on its ends. The connections 5 and 6 are inserted in the cylindrical wall 2 offset relative to each other; The areas of passage of the two throttling gaps 9 and 9' have, as shown in FIG. 8, an asymmetrical form with regard to the shorter co-ordinate. The internal width of the area of passage of the throttling gaps 9 and 9' increases with the distance from the connections 5 and 6, respectively. In this way, the stream of the first medium, despite the lateral position of the connections 5 and 6, is distributed or discharged therefrom uniformly over the entire length of the housing 1. In other respects, the path of the first medium corresponds to that shown and described with reference to FIGS. 3 to 5 (or 1 and 2).

We claim:

1. A heat exchanger having a cylindrical housing; tubes extending longitudinally through said housing, an inlet connection situated at one side of said housing, and an outlet connection situated at the other side of said housing; said tubes forming a tube assembly arranged centrally of said housing; a first partition lying against one side of said tube assembly and facing said inlet connection, and a second partition lying against the opposite side of said tube assembly and facing said outlet connection; said partitions forming between each other a flow space; a first throttling gap between a longitudinal edge of said first partition and the wall of said housing; and a second throttling gap between a longitudinal edge of said second partition and the wall of said housing; one surface of said tube assembly being in communication with said inlet connection substantially only by said first throttling gap, and another surface of said tube assembly being in communication with said outlet connection substantially only by said second throttling gap; a first stabilisation space in said housing situated between said inlet connection and said first throttling gap; a second stabilisation space in said housing, situated between said second throttling gap and said outlet connection; and a third stabilization space between said first gap and said one surface.

2. Heat exchanger according to claim 1; and a fourth stabilisation space between said another surface of said tube assembly and said second throttling gap.

3. Heat exchanger according to claim 1, in which said tube assembly (40) has a rectangular cross-section.

4. Heat exchanger according to claim 1, in which the area of passage of said first throttling gap is smaller than that of said second throttling gap.

5. Heat exchanger according to claim 1 in which the width of the said throttling gaps increases with the distance from said connections.

6. Heat exchanger according to claim 1, in which the wall of said housing has a jacket in the region of said first stabilisation space and in the region of the inlet side of said tube assembly; the intermediate space between said wall and said inner wall part being in communication with said second stabilisation space.

7. Heat exchanger according to claim 2, in which the wall of said housing has an inner jacket in the region of said first stabilisation space and in the region of the inlet side of said tube assembly; the intermediate space between said wall and said jacket being in communication with said second stabilisation space as well as with said fourth stabilisation space.

i i I I i 

1. A heat exchanger having a cylindrical housing; tubes extending longitudinally through said housing; an inlet connection situated at one side of said housing, and an outlet connection situated at the other side of said housing; said tubes forming a tube assembly arranged centrally of said housing; a first partiTion lying against one side of said tube assembly and facing said inlet connection, and a second partition lying against the opposite side of said tube assembly and facing said outlet connection; said partitions forming between each other a flow space; a first throttling gap between a longitudinal edge of said first partition and the wall of said housing; and a second throttling gap between a longitudinal edge of said second partition and the wall of said housing; one surface of said tube assembly being in communication with said inlet connection substantially only by said first throttling gap, and another surface of said tube assembly being in communication with said outlet connection substantially only by said second throttling gap; a first stabilisation space in said housing situated between said inlet connection and said first throttling gap; a second stabilisation space in said housing, situated between said second throttling gap and said outlet connection; and a third stabilization space between said first gap and said one surface.
 2. Heat exchanger according to claim 1; and a fourth stabilisation space between said another surface of said tube assembly and said second throttling gap.
 3. Heat exchanger according to claim 1, in which said tube assembly (40) has a rectangular cross-section.
 4. Heat exchanger according to claim 1, in which the area of passage of said first throttling gap is smaller than that of said second throttling gap.
 5. Heat exchanger according to claim 1 in which the width of the said throttling gaps increases with the distance from said connections.
 6. Heat exchanger according to claim 1, in which the wall of said housing has a jacket in the region of said first stabilisation space and in the region of the inlet side of said tube assembly; the intermediate space between said wall and said inner wall part being in communication with said second stabilisation space.
 7. Heat exchanger according to claim 2, in which the wall of said housing has an inner jacket in the region of said first stabilisation space and in the region of the inlet side of said tube assembly; the intermediate space between said wall and said jacket being in communication with said second stabilisation space as well as with said fourth stabilisation space. 